The 3 columns in color are computed by VizieR, and are not part of the original data.

Note: USNO-A2.0 contains 526,280,881 sources, and is based on a re-reduction of the Precision Measuring Machine (PMM) scans from POSS-I O and E plates (>=-18°) and SRC-J and ESO-R plates (<=-20°). USNO-A2.0 was created by Dave Monet () and collaborators at Flagstaff Station, U.S. Naval Observatory.
The major difference between USNO-A2.0 and its previous version USNO-A1.0 is that A1.0 used the Guide Star Catalog as its reference frame whereas A2.0 uses the ICRF as realized by the USNO ACT catalog (Urban et al. 1997). The VizieR search engine uses an on-line compressed version (3.6Gbytes) which was generated at CDS.

Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	USNO-A2.0	RAJ2000 deg	DEJ2000 deg	ACTflag	Mflag	Bmag mag	Rmag mag	Epoch yr
1	6.968	18 26 49.90944	+51 08 21.2424	1350-09679299	276.707956	+51.139234			16.3	9.5	1953.619
2	7.364	18 26 49.81272	+51 08 20.7204	1350-09679282	276.707553	+51.139089			12.2	11.3	1950.383

%0a%0a%3cP%3e%0a%3cFONT%20SIZE=%27-1%27%3e%3cEM%3e%3cFONT%20COLOR=%27#0000FF%27>%3cB%3eNote:%20The%20%3cB%3eGuide%20Star%20Catalog%20has%20been%20constructed%20to%20support%20the%20%0aoperational%20need%20of%20the%20Hubble%20Space%20Telescope.%0aIt%20contains%20over%2025%20million%20positions%20for%20about%2019%20million%0aobjects,%20of%20which%20more%20than%2015%20million%20are%20classified%20as%20stars.%0aThe%20version%20%3cB%3e1.2%20is%20a%20new%20astrometric%20reduction%20which%20results%20in%0aabsolute%20position%20errors%20about%200.3-0.4%20arcsec.%0a%28see%20GSC%20pages%20at%20URL%20http://www-gsss.stsci.edu/gsc/gsc.html%29%0a%3cP%3e%0a

Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	GSC	RAJ2000 deg	DEJ2000 deg	PosErr arcsec	Pmag mag	e_ mag	n_	Class	Plate	Epoch yr
1	6.77	18 26 49.8768	+51 08 20.544	0353800106	276.70782	+51.13904	0.4	13.96	0.40	1	3	02RV	1983.374
2	7.24	18 26 49.8312	+51 08 20.760	0353800106	276.70763	+51.13910	1.2	14.75	0.40	1	3	01H8	1983.352
3	7.36	18 26 49.8192	+51 08 20.796	0353800106	276.70758	+51.13911	0.3	13.42	0.40	1	3	00TB	1983.349

%0a%0a%3cP%3e%0a%3cFONT%20SIZE=%27-1%27%3e%3cEM%3e%3cFONT%20COLOR=%27#0000FF%27>%3cB%3eNote:%20The%20%3cB%3eGSC-ACT%20%3cEM%3e%28or%20%3cB%3eGSC1.3%29%0ais%20a%20recalibration%20of%20the%20%3cB%3e<%25E%20I/220%7cGSC1.1>,%20the%20catalogue%20constructed%20%0ato%20support%20the%20operational%20need%20of%20the%20Hubble%20Space%20Telescope,%0awith%20the%20%3cB%3e<%25E%20I/246%7cACT>,%20the%20combination%20of%20the%20Astrographic%20Catalogue%0aand%20the%20%3cB%3e%3cEM%3eTycho%20catalogue%20derived%20from%20the%20%3cEM%3e<%25E%20I/239%7cHipparcos>%0amission;%20see%20http://www.projectpluto.com/gsc_act.htm%20for%20more%20details%0aabout%20this%20recalibration.%0a%3cP%3e%0a%22>

>	\BegDIVclass='sort-down ' </A>
dec Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	GSC	RAJ2000 deg	DEJ2000 deg	PosErr arcsec	Pmag mag	e_ mag	n_	Class	Epoch yr
1	6.52	18 26 49.8984	+51 08 20.400	0353800106	276.70791	+51.13900	0.4	13.97	0.40	1	3	1983.374
2	7.33	18 26 49.8480	+51 08 21.120	0353800106	276.70770	+51.13920	0.3	13.42	0.41	1	3	1983.349
3	7.69	18 26 49.8120	+51 08 21.264	0353800106	276.70755	+51.13924	1.2	14.75	0.40	1	3	1983.352

Note: The current version includes only the North (POSS-I plates)

Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	APM-ID	RAJ2000 deg	DEJ2000 deg	rmag mag	l_	rClass	rStel	rDiam arcsec	rEll	bmag mag	l_	bClass	bStel	bDiam arcsec	b-r mag	Mflag
1	4.390	18 26 50.05416	+51 08 14.4204	EO0770-0001802	276.708559	+51.137339	20.00	L	0				11.43		2	46.41	47.6	-8.57
2	5.665	18 26 49.98816	+51 08 20.1012	EO0770-0001706	276.708284	+51.138917	9.26		1	9.15	44.6	0.15	22.02	L	0			12.76
3	7.816	18 26 49.85736	+51 08 21.9624	EO0789-0506289	276.707739	+51.139434	5.67		1	8.60	59.4	0.27	7.25		1	5.87	60.5	1.58

%0a%0a%3cP%3e%0a%3cFONT%20SIZE=%27-1%27%3e%3cEM%3e%3cFONT%20COLOR=%27#0000FF%27>%3cB%3eNote:%20The%20construction%20of%20the%20%0a%3cB%3eGSC-II%20%0ais%20still%20in%20progress:%20this%0aversion%20has%20no%20proper%20motions,%20and%20the%20magnitude%20limits%20are%2018.5%20in%20F%20%28red%29%0aand%2019.5%20in%20J%20%28blue%29.%20The%20data%20are%20%3cB%3e%3cFONT%20COLOR=%27#0000CD%27>copyrighted,%20check%20%0athe%20%3cB%3edata%20use%20Policy.%0a%3cP%3e%0a

Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	GSC2.2	RA(ICRS) deg	DE(ICRS) deg	Epoch yr	Rmag mag	e_ mag	Bjmag [****ClosingBrace(s)Inserted****]
">

Bjmag

%22>%5cFONT SIZE=-1mage_
magClass

a
pixe

1 6.37118 26 50.27040+51 08 22.7004N011033318025276.709460+51.1396391990.486    10.71 0.423 19.04 0.22 2 6.84618 26 49.87440+51 08 20.6448N0110333578276.707810+51.1390681991.600 9.13 0.43    0 20.87 0.11 %0a%0a%3cP%3e%0a%3cFONT%20SIZE=%27-1%27%3e%3cEM%3e%3cFONT%20COLOR=%27#0000FF%27>%3cB%3eNote:%20The%20%3cB%3eUSNO-B%20Catalog%20presents%20positions,%20proper%20motions,%20%0amagnitudes%20un%20blue,%20red%20and%20infrared,%20as%20well%20as%20star/galaxy%20estimators%0afor%201,045,175,762%20objects%20derived%20from%203,648,832,040%20separate%20observations.%0aThe%20data%20were%20taken%20from%20scans%20of%207,435%20Schmidt%20plates%0ataken%20from%20various%20sky%20surveys%20during%20the%20last%2050%20years.%3cBR%3e%0aUSNO-B1.0%20catalog%20was%20created%20by%20Dave%20Monet%20and%20collaborators%0aat%20http://www.nofs.navy.mil/data/fchpix/%20%3cBR%3e%0a%3cB%3e%3cFONT%20COLOR=%27#EE0000%27>%20Note%20that%20the%20star/galaxy%20estimators%20may%20be%20mixed%20up%0a%20in%20dense%20regions.%0a%3cP%3e%0a

Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	USNO-B1.0	RAJ2000 deg	DEJ2000 deg	e_RAJ2000 mas	e_DEJ2000 mas	Epoch yr	pmRA mas/yr	pmDE mas/yr	Ndet	B1mag mag	R1mag mag	B2mag mag	R2mag mag	Imag mag
1	6.141	18 26 51.01944	+51 08 13.4232	1411-0289106	276.712581	+51.137062	999	269	1950.3	0	0	2	18.51	19.23
2	6.827	18 26 50.89008	+51 08 22.0812	1411-0289102	276.712042	+51.139467	999	999	1952.0	0	0	2	17.08	18.32
3	6.986	18 26 49.85880	+51 08 20.6808	1411-0289081	276.707745	+51.139078	53	266	1973.0	0	0	4	13.57	10.48	9.62		10.60
4	7.682	18 26 50.96952	+51 08 10.5828	1411-0289104	276.712373	+51.136273	564	818	1978.5	0	0	3		15.99	16.35	16.55
5	7.817	18 26 49.78008	+51 08 21.0732	1411-0289079	276.707417	+51.139187	182	436	1971.4	0	0	4	12.54	11.18	9.55	9.16
6	9.612	18 26 50.78280	+51 08 25.7028	1411-0289097	276.711595	+51.140473	22	941	1979.8	32	-46	3	17.04			15.79	15.84

%0a%0a%3cP%3e%0a%3cFONT%20SIZE=%27-1%27%3e%3cEM%3e%3cFONT%20COLOR=%27#0000FF%27>%3cB%3eNote:%20The%20Naval%20Observatory%20Merged%20Astrometric%20Dataset%20%28NOMAD%29%20contains%0aastrometric%20and%20photometric%20data%20for%20over%201%20billion%20stars%20derived%20from%0athe%20Hipparcos%20%28I/239%29,%20Tycho-2%20%28I/259%29,%20UCAC2%20%28I/289%29,%20and%20USNO-B1.0%0a%28I/284%29%20catalogs%20for%20astrometry%20and%20optical%20photometry,%20supplemented%0aby%202MASS%20%28II/246%29%20near-infrared%20photometry.%3cBR%3e%0a%3cFONT%20SIZE=%27-1%27%3eAn%20efficient%20remote%20query%20program%20%3cB%3efindnomad1%20is%0aavailable%20in%20the%20cdsclient%20%0apackage,%20for%20Unix/Linux%20platforms%0a%3cP%3e%0a

Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	NOMAD1	YM	RAJ2000 deg	DEJ2000 deg	r	pmRA mas/yr	[****ClosingBrace(s)Inserted****]
">

mas/yr&%">\BegDIVclass='sort-down ' </A>dece_
(...)pmDE
mas/yr

e_
(...)

Bmag
mag

r_

Vmag
mag

r_

Rmag
mag

r_

Jmag
mag

Hmag
mag

Kmag
mag

R

1 6.14218 26 51.019344+51 08 13.419961411-0293825..276.7125806+51.1370611B 0.0 0.0 0.0 0.018.510o    19.230e         2 6.82518 26 50.890008+51 08 22.080121411-0293821..276.7120417+51.1394667B 0.0 0.0 0.0 0.017.080o    18.320e         3 6.98618 26 49.858656+51 08 20.680081411-0293800..276.7077444+51.1390778B 0.0 0.0 0.0 0.0 9.620B    10.480e         4 7.68318 26 50.969328+51 08 10.579921411-0293823..276.7123722+51.1362722B 0.0 0.0 0.0 0.016.350B    16.550B         5 7.81518 26 49.780008+51 08 21.069961411-0293798YM276.7074167+51.1391861B 0.0 0.0 0.0 0.015.990Y15.130Y 9.160B14.42313.77213.451   6 9.60818 26 50.782656+51 08 25.699921411-0293816..276.7115944+51.1404722B 32.0 0.0 -46.0 34.017.040o    15.790B         %0a%0a%3cP%3e%0a%3cFONT%20SIZE=%27-1%27%3e%3cEM%3e%3cFONT%20COLOR=%27#0000FF%27>%3cB%3eNote:%20This%20version%20of%20the%20%0a%3cB%3eGSC-II%0ahas%20no%20proper%20motions,%20but%20the%20limits%20on%20brightness%20which%20existed%20on%0a%20%28F<18.5,%20B_j<19.5%29%20were%20removed.%0a%25The%20data%20are%20%3cB%3e%3cFONT%20COLOR=%27#0000CD%27>copyrighted,%20check%0a%25the%20%3cB%3edata%20use%20Policy.%0a%3cP%3e%0a

Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	GSC2.3	RAJ2000 deg	DEJ2000 deg	Epoch yr	Fmag mag	jmag mag	Vmag mag	Nmag mag	Class	a pix	e
1	6.374	18 26 50.27064	+51 08 22.7040	N11B018025	276.709461	+51.139640	1990.486		10.71			3	19.04	0.22
2	6.848	18 26 49.87440	+51 08 20.6484	N11B000578	276.707810	+51.139069	1991.600	9.13		11.15	9.39	3	20.87	0.11

%0a%0a%3cP%3e%0a%3cFONT%20SIZE=%27-1%27%3e%3cEM%3e%3cFONT%20COLOR=%27#0000FF%27>%3cB%3eNote:%20%20The%20limiting%20magnitude%20is%20about%2015.2%20in%20the%20GSC%20photometric%20system.%3cP%3e%0a